Engine trip for steam shovels



C. A. SHANCELLOR, L. G. McMANNAMA AND C. E. HOUGHTON. ENGINE TRIP FOR STEAM SHOVELS.

APPLICATION FILED FEB. 14, 1921.

Patented M. 3,1922.

4 SHEETSSH EET 1.

XNVEN OR6 ATTORN EY C. A. CHANCELLOR, L. G. McMANNAMA, AND C. E. HOUGHTON.

ENGINE TRIP FOR STEAM SHOVELS.

APPLCATION FILED FEB. 14, 1921.

Patented Oct. 3, 1922.

4 SHEETSSHE!:IT 2.

ATTORNEY C. A. CHANCELLOR, L. G. MCMANNAMA, AND C. E. HOUGHTON.

ENGINE TRIP FOR STEAM SHOVELS.

APPLICATION FILED FEB. 14, 1921.

ATTORNEY C. A. CHANCELLOR, L. G. McMANNAMA AND C. E. HOUGHTON.

ENGINE TRIP FOR STEAM SHOVELS.

' APPLICATION.F|LED FEB. I4, 192]- 942 Patented Oct. 3

ATTORNEY iii Patented out. a, rear,

CHESTER A. CHANCELLOR, LOREN G. IVIGMANNAMA, AND OAKLEY 3E. HOUGHTON, OF

MINDENMINES, MISSOURI.

ENGINE TRIP FOP, STEAM SHOVELS.

Application filed February 14, 1921.

To all iii/m it may concern Be it known that we, CiinsrrE-n A. CHAN- onLLon, LonnN G. lllolrlnrtnimr i, and Carrier ill. l-loucrrrorr, citizens of the United States, residing at Mindenmincs, in the coiu'ity oi Barton and State of Missouri, h ave invented new and useful Improvements in Engine Trips for Steam vShovels, off which the following is a specification.

This invention relates to steam shovels or excavators and has for its object the provision of means operated by certain movement of the dipper stick whereby to release the latch which holds the hinged bottom of the dipper or scoop.

An important object is the provision of mechanism of this character which is entirely automatic in action. so as to avoid any necessity for the employment of a craneman and which will, therefore economize on labor.

Another object is the provision of mechanism of this character which will operate automatically when the dipper stick is run out or extended to its maximum extent and which will also automatically operate when the dipper stick is retracted or run in slightly when the dipper stick is in a certaln angular position with respect to the ground, this latter mentioned feature being essential inasmuch as it obviates risk of inad rtently dumping the scoop or dipper during load- Another object is the provision of a device of this character which may be added an attzuzhi'nent to ordinary existing excavating devices of this type without involving :uiv alterations therein, the entire tripping mechanism being merely attachable.

An additional object is the provision of a device of this character in which the control of the dumping dipper is positive, which possesses the advantage 01? being simple and inexpensive in construction and installation, highly el'licient in use, durable 111 service, and a general in'iprovement 1n the art.

lVith the above and other objects and advantages in view, the invention consists in the details of construction to be hereinafter more fully described and claimed and illustrated in the accompanying drawings in which Figure 1 is a side elevation oil a portion of a steam shovel having our device applied thereto end showing it in loading position,

Serial No. 4144,751.

Figure 2 is a omitted,

Figure 3 is a side elevation showing the parts in position ready to dump,

Figure 4- is a view similar to Figure 3 showing the trip means,

Figure 5 is a fragmentary side elevation showing a dilierent position of the latch pawl,

Figure 6 is a similar view showing another position of the latching pawl, and

Figure 7 is across sectional view on the line '77 of Figure 3. Referring more particularly to the drawings, the letter A designates the end portion of the supporting boom Off a steam shovel of ordinary type, B designates the dipper stick carrying the usual rack C engaged by a pinion l), E designates the guide plate, designates the pulley carried by the boom, lg designates the hoisting cable trained over the pulley, and H designates the dipper or scoop conne d by a sheave l with the cable G and having the usual hinged bottom J held in place by a sliding keeper or latch K. Ordinarily a rope or the like is connected with the latch K for releasing the hinged bottom of the dipper or scoop when it is desired to dump the latter.

In carrying out the invention we provide a bar it) mounted for longitudinal move ment above and in spaced relation to the dipper stick B and this bar is formed with series otspaced transverse notches 11. One end of [lllS bar is pivotally connected by a slot and pin connection with a lever 13 pivoted intermediate its ends, as shown at it, near the tree end or the dipper stick. The lower end ot this lever 12% has connected therewith a flexible member such as a chain 15 which is in turn connected with the latch K of the dipper. The other end of the bar 10 is pivotally connected with a lever 16 which is pivoted intermediate its ends upon a stud or post 17 rising from the dipper stick. The other end of the lever 16 is com nected with a plunger rod 18 slidable through the arms of a ll-shaped bracket 19. Secured on this plunger rod is a collar 20 engaging against one end of a coil spring 21 which encircles the plunger rod and abuts at its other end against the outermost arm of the ti -shaped bracket. The "function of the spring 21 is to hold the bar 10 normally in plan View, the boom being such oosition that the lever l3rwill extend at llO right angles to the dipper stick B so as not to pull upon the chain 15. This is the normal position of the parts when. the bottom J oil? the dipper is closed and the parts are intended to remain in this position while the dipper or scoop goes through the necessary movement to effect loading thereof.

Secured upon the guide E is a hollow housing 22 preferably cylindrical in shape and having its upper end 23 closed and formed in one side with a vertical slot 2%. Located within this housing is a plunger cup 25 which carries a laterally extending stem 26 upon which is pivoted a depending pawl 27 of the shape shown. This particular shape of the pawl is for the purpose ofthrowing its center of gravity to one side of the axis of the housing tor a purpose to be hereinafter described. Engaging within the cup 25 is a coil spring 28 which engages an adjusting cup member 29 within the upper portion of the housing, the member 29 being in turn engaged by an adjusting screw 30 threaded through the closed top 019 the housing. The purpose of this spring 29 is to permit vertical movement of the cup member 25 and consequently the pawl 27 under certain conditions, as will be 6X- plained.

In the operation of the device it will be seen that under normal conditions with the dipper stick inclined downwardly, as shown in Figure 1., the tripping mechanism above described is entirely inactive. W hen the dipper or scoop has been lowered and it is desired to dump the same, the dipper stick is of course elevated to the proper position, after which the usual engine driven means is operated to run the dipper stick out or extend it over the wagon or other vehicle to receive the load. l l hen the dipper stick is run out to the end of its movement the plunger 18 will engage against the guide E whereupon the lever 16 will be rocked upon its pivot 17 which will result in longitudinal movement of? the bar 10 toward the dipper and this will of course result in swinging); the lever 13 upon its pivot 14 into the position shown in Figure i. whereupon the lower end of the lever 13 will exert a pull upon the chain 15 and cause retraction of the latch it so that the hinged bottom of the dipper will swing downwardly to release the load.

It is, however, possible to dump the dipper without running out the dipper stick to its maximum extent. This, however, cannot be accomplished until the dipper stick has been elevated to a predetermined angle with respect to the horizontal, this angle being determined by the specific construction and consequent center of gravity of the pawl 27. When this angle has been determined and the parts correspondingly adjusted, it will be seen that when the dipper stick. is swung to the proper angular position, the pawl 27 will bear upon the top oi the bar 10. s hen the dipper stick ii is run out part way, or as far as desired except to its maximum extent, there will be no action on the part of the pawl 27 'as the notched bar 10 will ride idly beneath its end. When it is desired to dump the dipper it is merely necessary that the dipper stick moving mechanism be reversed to retract the dipper stick few inches whereupon one or the notches 11 will engage the heel of the pawl 27 and hold the member 10 stationary. Subsequent retraction of the dipper stick will then of course result in moving the lever 13 rear-.vardly and this will of course pull upon the chain 15 and release the latch K.

ll hen it is subsequently desired to retract the dipper stick still more so as to prepare 'lor the nest loading operation, continued retraction of the dipper stick will result in swinging the pawl 27 into the position shown in Figure 6 and then into the position shown in i i ure the slot and spring 28 permittin the necessary vertical movement or? the pawl. l i hen the dipper stick it then run out the pawl will be moved from the position shown in Figure 5 to the position shown in Figure 6 and then to the position shown in Figure without in any ay ali'ecting the bar 10. is long as the dipper stick B is inclined downwardly, as for example shown in Figure 1, the pawl 27 will be out of eng ment with the bar 10 so that the dipper stick may be run in and out freely without any danger whatever of j.

operating trip.

From the foregoing description and a study at the drawi it will be apparent that we have thus pro *ide-d a simply constructed and, consequei .ly inex ensive trip attachment for steam shovels or excavators which is very easy to install, which requires no alterations in the structure of the steam shovel. itself and which will operate very e'l'liciently, especially as the trip positively power actuated.

ll hile we have shown and described the preferred embodiment our invention, it is of course to be understood that we reserve the right to make such changes in the form,

construction, and arrangement of parts as will not depart from the spirit of the in vention or the scope of the subjoined claims Having thus described our invention, we claim:

1. In a steam shovel, the combination oi. a boom, a dipper and dipper stick, a guide on said. boom for the dipper stick, a dipper door on the dipper provided with a latch, longitudinally movable bar carried by the dipper stick, and an operative connection between the forward end of. said bar and. the retaining latch oi? the dipper door, and means con nected with the other end of the bar and engageable with the guide upon the outward movement of the dipper stick to its.

maximum extent whereby to move the bar to release said latch.

2. In a steam shovel including a boom, a dipper stick, a stationary guide on the boom, a dipper and a dipper door having a latch;

a trip mechanism con'iprising a longitudinally movable bar carried by the dipper stick, an operative connection between the forward end of said bar and the retaining latch oi. the dipper door, and means connected with the other end of the bar and engageable with the guide upon the outward movement of the dipper stick to its maximum extent whereby to move the bar to release said latch.

3. In a steam shovel including a boom, a dipper stick, a stationary guide on the boom, a dipper and a dipper door hai'ing a latch; a trip mechanism comprising a longitudinally movable bar carried by the dipper stick, an operative connection between the forward end of said bar and the retaining latch of the dipper door, and means connected with the other end of the bar and engageable with the guide upon the outward movement of the dipper stick to its maximum extent whereby to move the bar to release said latch, said means comprising a pivoted lever connected with the second mentioned end of said bar at one end and carrying a spring pressed plunger at its other end engageable with the guide.

4. In a steam shovel including a boom, a dipper stick, a stationary guide on the boom, a dipper and a dipper door having a latch; a trip mechanism comprising a longitudinally movable bar carried by the dipper stick, an operative connection between the forward end of said bar and the retaining latch of the dipper door, and means connected with the other end of the bar and engageable with the guide upon the outward movement of the dipper stick to its maximum extent whereby to move the bar to release said latch, said means comprising a le' 'ver pivoted intermediate its ends upon the dipper stick and connected at one end with the second mentioned end of said bar, a bracket carried by the dipper stick, a plunger carried by the other end of said lever and slidable through said bracket and a spring urging said plunger toward the guide to hold the bar in inactive position.

5. In a steam shovel including a boom, a dipper stick, a dipper carried by the stick and having a door, a latch device normally holding said door closed, and a guide stationary upon the boom, a trip mechanism comprising a lever pivoted intermediate its end upon the forward end of the dipper stick, a flexible member connected with the lower end of said lever and with the latch of the dipper door, a bar disposed above and in spaced relation to the dipper stick and connected with the other end of said lever, a lever pivoted intermediate its ends upon the other end portion of the dipper stick and pivotally connected at one end with the other end of said bar, and a spring pressed plunger carried by the other end of said second named lever and engageable with the guide upon the outward movement of the dipper stick to its maximum extent whereby to move the bar to swing said first named lever.

6. In a steam shovel structure including a boom, a dipper stick, a dipper carried by the stick and having a door, a latch device normally holding the door closed, and a stationary guide upon the boom, a trip mechanism comprising a lever pivoted intermediate its ends upon the forward end of the dipper stick, a flexible member connected with the lower end of said lever and with the latch of the dipper door, a bar disposed above and in spaced parallel relation to the dipper stick and connected with the other end of said lever, a lever pivoted intermediate its ends upon the other end portion of the dip per stick and pivotally connected at one end with the other end of said bar, a spring pressed plunger carried by the other end of said second named lever and engageable with the guide upon the outward movement of the dipper stick to its maximum extent whereby to move the bar to swing said first named lever, a member secured upon the guide, and a vertically movable downwardly spring pressed swingable pawl carried by said last named member and engageable with said bar, the bar being formed with notches engageable with the end of the pawl.

In testimony whereof we, allix our signatures.

CHESTER A. CHANCELLOR. LOREN G. MCMANNAMA. CARLEY E. HOUGHTON. 

